Pioneer Deep Space Station · Photo: NASA · Public domainFort Irwin’s winters are milder than most of the U.S.; July afternoons average 103°
A typical July afternoon reaches 103°, a January night drops to 37°.
A year in Fort Irwin at a glance
Each month’s typical high and low, and what it brings.
What stands out about Fort Irwin’s climate
Compared with towns across the U.S., with Fort Irwin’s place in California beside it.
What a year in Fort Irwin feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 5 inches of rain a year
February is the wettest month and June the driest.
Rain + melted snow by month
Inches of water
Living with Fort Irwin’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 9a.
Months with highs of 62–84° and lows of 40° or more: February, March, April, October and November. 21 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Fort Irwin from natural hazards, river flooding is the largest share (73%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Fort Irwin and similar climates
TownRatings has no climate map of the towns around Fort Irwin yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Fort Irwin averaged 2.2° warmer than the 1900s. The biggest change is in September (+3.2°).
A bigger shift than in 97% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Fort Irwin compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Fort Irwin’s place among California’s.
Fort Irwin weather by month
Highs, lows and precipitation from NOAA’s grid at Fort Irwin’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 59° | 37° | 1.0" | 44° – 54° |
| February | 63° | 40° | 1.2" | 45° – 59° |
| March | 70° | 46° | 0.7" | 51° – 64° |
| April | 77° | 51° | 0.2" | 58° – 68° |
| May | 87° | 59° | 0.1" | 64° – 80° |
| June | 97° | 68° | 0.0" | 76° – 88° |
| July | 103° | 75° | 0.2" | 84° – 93° |
| August | 101° | 74° | 0.2" | 84° – 91° |
| September | 94° | 67° | 0.2" | 76° – 85° |
| October | 81° | 55° | 0.3" | 64° – 74° |
| November | 68° | 44° | 0.4" | 47° – 62° |
| December | 57° | 36° | 0.8" | 43° – 52° |
| Year | 80° | 54° | 5.2" |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 64° to 80°. August is the most reliable, staying within 7°.
Where Fort Irwin’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Fort Irwin’s center.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Fort Irwin’s climate
What is the weather like in Fort Irwin?
A typical July afternoon reaches 103°, a January night drops to 37°. Milder January nights than 85% of U.S. towns; hotter July afternoons than all but 99 U.S. towns.
How cold does it get in Fort Irwin in winter?
December nights average 36°. In the coldest December of the last 30 years the month averaged 43°.
How hot does it get in Fort Irwin?
July, with a typical high of 103°. 90° days are rare.
What growing zone is Fort Irwin in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 20°.
What is the best time of year to visit Fort Irwin?
By one simple rule (highs of 62–84° and lows of 40° or more), February, March, April, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Fort Irwin getting warmer?
Yes: 1991–2020 averaged 2.2° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 97% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Fort Irwin.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.